Ocular Allergies- Classification, Signs and symptoms, Pathogenesis, Treatment,

1. OCULAR ALLERGY
CCDH MEETING
MARCH 2014
Dr Michael Minogue

2. CLASSIFICATION
 acute conjunctival allergy
 seasonal allergic conjunctivitis
 perennial allergic conjunctivitis
 vernal kerato-conjunctivis
 atopic kerato-conjunctivis
 giant papillary conjunctivitis
 contact allergic conjunctivis

3. SYMPTOMS
 itch
 conjunctival hyperaemia
 tearing
 conjunctival oedema
 mucus discharge
 lid oedema
 photophobia
 eye rubbing
 blurred vision

4. SEASONAL ALLERGIC CONJUNCTIVITIS
 sub-acute onset
 lasts days to weeks
 seasonal allergens- grass, tree pollens, moulds
 associated with hay-fever/allergic rhinitis
 IgE mediated, type 1 allergic response
 80% of patients are under 30 years of age
 strong personal or family history of allergy
 affects 5 to 20% of population

5. Cytokine regulation of the acquired immune response

7. ACUTE CONJUNCTIVAL ALLERGY
 sudden onset eg allergy to cats
 self limited- usually settles within 24hrs
 conjunctival and lid oedema can be alarming to
patient

8. PERENNIAL ALLERGIC CONJUNCTIVIS
 persistent symptoms but can have seasonal spikes
 triggered by house-dust mites,moulds,animal
allergens
 IgE mediated
 mostly young adults (slightly higher prevalence in
males
 often personal or family history of allergy

9. VERNAL KERATOCONJUNCTIVITIS
 a disease with some allergic components in
combination with a chronic inflammatory
response
 comprises 2% of cases of ocular allergy
 mostly affects young boys under 10 years of age
 most common in hot climates
 tarsal (cobblestone papillae) and limbal (trantas
dots) variants
 personal or family history of atopy in 50%
 positive skin test in only 50%

10. Upper tarsal conjunctiva of patient withVKC

11. PATHOPHYSIOLOGY
1. Th2 lymphocytes mediate hyperproduction of IgE
via Il4 . They also mediate differentiation and
activation of mast cells and eosinophils via Il3 and
Il5 respectively.
2. Over-expression of oestrogen and progesterone
receptors in the conjunctiva of VKC patients may
explain improvement with onset of puberty.
3. There may be involvement of neural factors such as
substance P and NGF in pathogenesis
4. Hypersensitivity to wind, dust, sun may have a role.
5. Probable genetic component - a reduced level of tear
film histaminase has been found.

12. CLINICAL FEATURES OF VKC
 giant papillae/ trantas dots
 ropy mucus discharge common
 SPK and shield ulcers may be related to
epithelial toxic effects of eosinophilic major basic
protein, eosinophilic cationic protein and
peroxidase
 ptosis can occur
 steroid induced glaucoma and cataract can occur

13. ATOPIC KERATOCONJUNCTIVITIS
 associated with atopic eczema
 often periocular with lid margin involvement
 male predominance, age 30-50
 often strong family history of allergy (atopic
eczema an asthma)
 can have associated ocular surface disease
(conjunctival scarring, corneal PEK, corneal
vascularization)
 herpetic keratitis can occur in 15% of patients
 keratoconus can occur in 5-15% of patients
 affects 3% of population

14. Severe periocular and lid involvement of AKC

15. ATOPIC KERATO-CONJUNCTIVITIS (CONT.)
 eyelid skin thickened with lichenification
 can have associated punctal ectropion/ ptosis
 lower fornix conjunctival papillae
 potential visual loss from corneal disease,
cataract, steroid, induced glaucoma
 type I and type IV hypersensitivity
 increased mast cells, eosinophils, CD4+ T cells
(Th1 and Th2), monocytes, fibroblasts

16. Limbal gelatinous hyperplasia in AKC

17. GIANT PAPILLARY CONJUNCTIVITIS
 non infectious inflammation disorder of the
superior tarsal conjunctiva
 named for size of papillae (> 1mm in diameter)
 papillae > 0.3 mm are considered abnormal
 occurrence 1 to 5% of soft contact lens wearers,
1% of hard contact lens wearers
 average time of onset is 8 months for soft contact
lens wearers
 can occur secondary to exposed sutures, elevated
subepithelial calcium plaques, ocular prosthetics
 often associated history of atopy

18. Giant papillary conjunctivitis Advancing conjunctival thickening and
papillary formation
Giant papillae

19. SYMPTOMS AND SIGNS
 early - mild irritation, scanty mucus discharge
 late - blurred vision secondary to lens coating
with mucus and protein
- increased mucus accumulation
- persistent protein body sensation
- ocular itching after contact lens removal
- complete contact lens intolerance

20. PATHOGENESIS
 probably due to combined effect of mechanical
trauma followed by repeated immunological
presentation of foreign antigens in the form of
surface deposits or environmental agents
 combined type I and type IV hypersensitivity
reactions
 infiltration of conjunctival substantia propria by
eosinophils, mast cells (T cell independent, skin
type), basophils, lymphocytes and plasma cells

21. TREATMENT
 removal of cause
 change to daily wear contact lenses of RGP lenses
 hydrogen peroxide disinfection probably best
 more frequent enzymatic cleaning of soft lenses
 topical corticosteroid in acute phase (along with
contact lens discontinuation)
 good prognosis

22. TREATMENT
1. non specific
 allergen avoidance
 air conditioning
 cold compresses
 cold artificial tears
2. topical or oral antihistamines
 eg OTC Naphazoline-Antazoline
3. combined antihistamine / mast cell stabilizers
 Olapatadine (Patanol)- preservative BAK
 Ketotifen (Zaditen) – preservative free
4. mast cell stabilizers
 Cromoglycate (Opticrom)
 Lodoxamide (Lomide)

23. TREATMENT (CONT.)
5. topical steroid
 FML
 Maxidex
 Prednefrin Forte
6. calcineurin inhibitors
 Cyclosporine (Restasis)
 Tacrolimus
7. systemic immuno supression
 oral Prednisone
 oral Cyclosporine
8. Plasmapheresis

24. QUESTIONS
1. Which of the following symptoms is associated with ocular allergy?
a. itch
b. tearing
c. conjunctival hyperaemia
d. all of the above
2. Which of the following drug is not generally used in the treatment of
conjuctival allergy?
a. topical antihistamine / mast cell stabilizer
b. topical steroid
c. topical calcineurin inhibitors
d. NSAIDS
3. Which of the following can be associated with AKC and VKC?
a. keratoconus
b. bacterial keratitis
c. glaucoma
d. cataract
e. all of the above